Book of 99 (Relax Gaming) Slot Review

Book of 99: Slot Overview 

In an overcrowded sea of “book-style” slot games, Relax Gaming’s Book of 99 emerges as a bold outlier, not because of a radically different gameplay concept, but due to its staggering 99% RTP – an eye-popping figure that eclipses almost every other slot on the market. Launched on May 4, 2021, this 5-reel, 3-row, 10-payline slot is set in a mythological version of Ancient Greece and wraps its familiar mechanics in a refreshingly generous mathematical model. 

With high volatility and a max win of 12,075x, Book of 99 marries traditional “book” mechanics with a wild collection meter, offering a blend of short-term thrill and long-term progression. It’s a slot that respects the player, catering to those who want to spin for leisure and those who meticulously chase value.

Design and Graphics 

Relax Gaming has always prided itself on clean, visually compelling slot design, and Book of 99 doesn’t disappoint. The game transports players to a beautifully drawn Grecian temple backdrop, flanked by stone columns and stormy skies. The artwork strikes a balance between mythical ambiance and cartoonish charm. Heroes and villains from Greek legend appear on the reels: from the fearsome Lamia and a hulking cyclops to classic male and female adventurers.The user interface is crisp and intuitive. A vertical wild collection meter on the left side of the reels tracks progress toward triggering the bonus round, giving players a visual sense of achievement. Everything from the icons to the animation sequences feels polished, even if the base game visuals aren’t quite as dynamic as some higher-budget slots.

Gameplay Mechanics 

Book of 99 operates on a 5×3 reel grid with 10 fixed paylines, following the template made famous by games like Book of Ra and Book of Dead. Wins are formed by landing matching symbols from left to right starting on reel 1, with low-paying symbols (10 through A) needing at least 3-of-a-kind and premiums paying from 2-of-a-kind upwards. 

One standout feature here is the use of a book symbol that serves a dual role: it functions as both the wild and scatter. This symbol can substitute for any pay symbol and also triggers the Free Spins feature when 3 or more appear on the reels. 

But what truly differentiates Book of 99 is its wild collection system. Each wild collected in the base game is counted on the left-hand meter, and when you collect 99 wilds, you’re automatically awarded 10 Free Spins, without needing the scatter trigger. This adds a subtle layer of strategy and builds a feeling of momentum during base gameplay – a clever way to enhance engagement.

Sound and Music 

The soundtrack of Book of 99 complements the mythological setting beautifully. Relax Gaming has implemented a pulsing, rhythmic beat paired with melodic undertones, evoking the kind of tension and grandeur you might expect in an epic Greek tale. 

The music isn’t intrusive but builds nicely during key moments like wins or when the free spins are near. Sound effects are tightly synced with the animations – a small but important detail that enhances the sense of immersion. It’s not an overly dramatic score, but it adds character and atmosphere to every spin.

Bonus Features 

Expanding Symbol Free SpinsThe hallmark feature of all “book” slots is present here – Expanding Symbols in Free Spins. When triggered either by landing 3+ book symbols or collecting 99 wilds, the game grants 10 free spins. Before the feature starts, one pay symbol is randomly chosen to become the special expanding symbol for the entire round. 

This symbol doesn’t need to appear on adjacent reels to pay during the bonus round. Instead, it expands to cover entire reels when enough are present to form a win, paying scatter-style across all positions. It’s a thrilling mechanic that can result in enormous payouts, especially when high-paying symbols are selected. 

Wild Collection Feature 

Perhaps the most innovative twist in Book of 99 is the collection system. Every time a wild lands in the base game, the wild meter increases by one step. When this reaches 99, players automatically get a Free Spins round, mimicking the scatter trigger but rewarding persistence rather than luck. 

This dual-trigger system ensures that even during dry spells, players feel they are making meaningful progress toward the bonus game – an elegant solution to volatility fatigue. And yes, Free Spins can also be retriggered with another set of 3 or more books, just like in classic book slots.

Betting Options and Payouts 

Relax Gaming accommodates all types of players with a wide betting range: from 0.10 to 100 per spin. This flexibility allows casual spinners and high-rollers alike to engage with the game on their own terms. 

The maximum win is an impressive 12,075x your stake, which is well above average for book-style slots. Thanks to the 99% RTP – a figure that dwarfs the typical 96% benchmark – the long-term value is exceptional. Add in a hit frequency of 29.83%, and you’ve got a slot that delivers wins relatively often, even if they tend to vary in size due to the high volatility. 

Wins with 5-of-a-kind premium symbols can yield between 75x to 500x your bet, making full-screen combinations in free spins a highly lucrative goal. These payout tiers are in line with the traditional book structure but are amplified by the RTP and hit rate.

Conclusion 

Book of 99 is more than just another “book” clone – it’s a well-calculated reinvention of the format. Relax Gaming has demonstrated that you don’t need groundbreaking features to innovate. Sometimes, rebalancing the math model and refining the structure is enough to create something exceptional. 

The wild collection system adds a level of long-term engagement missing in many high-volatility slots, and the expanding symbol free spins remain as exciting as ever. Coupled with the record-setting 99% RTP, this game becomes irresistible for value-seeking players who appreciate strong fundamentals and elegant design. 

It’s an ideal choice for those looking to fulfill wagering requirements, thanks to its generous RTP and moderate hit frequency. Whether you’re a veteran of the “book” genre or a newcomer curious about high-value slots, Book of 99 offers a compelling, rewarding experience. Simply put, it’s one of the most player-friendly games in its category – a true standout in a saturated market.